In order to study whether the endothelial cells (ECs) with lipid peroxidation induced by diamide can express and secrete macrophage inflammatory protein 1α (MIP-1α), the expression of MIP-1α protein in the cells was detected by cell enzyme-linked immunosorbent assay (ELISA) and that of MIP-1α mRNA was determined by cell in situ hybridization and nuclease S1 protection assay after the ECs were exposed to different concentrations of diamide for 4 h. The chemotactic activity of MIP-1α was tested by micropore filter method using modified Boyden chambers. Cell ELISA showed that the expression of MIP-1α protein in endothelial cells exposed to 1 μmol/L, 5 μmol/L and 10 μmol/L diamide was 1.9-fold, 2.3-fold and 1.7-fold respectively as much as that in the control cells, which was statistically significant by analysis of variance. In situ hybridization revealed that the mRNA expression of ECs treated with 1 μmol/L, 5 μmol/L and 10 μmol/L diamide was 1 3-fold, 3.0-fold and 1.7-fold as much as that in the control group, which had statistical significance ( F =188.93, P <0.01). The mRNA expression in 5 μmol/L dimide treated ECs, measured by nuclease S1 protection assay, was 3.4-fold as much as that in the control group( t =8 70, P <0 05). Chemotactic response(99.50±4.31 μm) to the culture medium conditioned by 5 μmol/L diamide treated ECs , which was stronger than that(66.47±3.25 μm) conditioned by the ECs ( F =404.31, P <0.05), was significantly decreased ( F =192.25, P <0.05) after adding MIP-1α antibody. It suggests that diamide, a lipid peroxidation inducer, could stimulate ECs to produce high level of MIP-1α, and might play an important role in atherogenesis by promoting the migration of peripheral blood monocytes into arterial intima.
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